The Probert Encyclopaedia of General Information

CALENDAR

A calendar (named from the Latin calendarium, from calendce, the first day of the month), is a record or marking out of time as systematically divided into years, months, weeks, and days.

The periodical occurrence of certain natural phenomena gave rise to the first division of time, the division into weeks being the only purely arbitrary partition. The year of the ancient Egyptians was based on the changes of the seasons alone, without reference to the lunar month, and contained 365 days divided into twelve months of thirty days each, with five supplementary days at the end of the year.

The Jewish year consisted of lunar months of which they reckoned twelve in the year, intercalating a thirteenth when necessary to maintain the correspondence of the particular months with the regular recurrence of the seasons.

The Greeks in the earliest period also reckoned by lunar and intercalary months, but after one or two changes adopted the plan of Meton and Euctemon, who took account of the fact that in a period of nineteen years, the new moons return upon the same days of the year as before. This period of nineteen years was found, however, to be about six hours too long, and subsequent calculators still failed to make the beginning of the seasons return on the same fixed day of the year. Each month was divided into three decads.

The Romans at first divided the year into ten months, but they early adopted the Greek method of lunar and intercalary months, making the lunar year consist of 354, and afterwards of 355 days, leaving ten or eleven days and a fraction to be supplied by the intercalary division. This arrangement continued until the time of Julius Caesar. The first day of the month was called the calends. In March, May, July, and October the 15th, in other months the 13th, was called the ides. The ninth day before the ides (reckoning inclusive) was called the nones, being therefore either the 7th or the 5th of the month. From the inaccuracy of the Roman method of reckoning the calendar came to represent the vernal equinox nearly two months after the event, and at the request of Julius Caesar, the Greek astronomer Sosigenes with the assistance of Marcus Fabius, contrived the so-called Julian calendar. The chief improvement consisted in restoring the equinox to its proper place by inserting two months between November and December, so that the year 707 (46 BC), called the year of confusion, contained fourteen months.

In the number of days the Greek computation was adopted, which made it 365.25. To dispose of the quarter of a day it was determined to intercalate a day every fourth year between the 23rd and 24th of February. This calendar continued in use among the Romans until the fall of the empire, and throughout Christendom until 1582.

By this time, owing to the cumulative error of eleven minutes, the vernal equinox really took place ten days earlier than its date in the calendar, and accordingly Pope Gregory XIII issued a brief abolishing the Julian calendar in all Catholic countries, and introducing in its stead the one now in use, the Gregorian or reformed calendar. In this way began the new style, as opposed to the other or old style. Ten days were to be dropped; every hundredth year, which by the old style was to have been a leap year, was now to be a common year, the fourth excepted; and the length of the solar year was taken to be 365 days, five hours, forty-nine minutes, and twelve seconds, the difference between which and subsequent observations is immaterial. The new calendar was adopted in Spain, Portugal, and France in 1582; in Catholic Switzerland, Germany and the Netherlands in 1583; in Poland in 1586; in Hungary in 1587; in Protestant Germany, Holland, and Denmark in 1700; in Switzerland in 1701; in England in 1752; and in Sweden, 1753.

In the English calendar of 1752, also, the 1st of January was now adopted as the beginning of the legal year, and it was customary for some time to give two dates for the period intervening between 1st January and 25th March, that of the old and that of the new year, as January 1752/3. Russia alone retained the old style, which by 1906 differed twelve days from the new.

In France, during the revolution, a new calendar was introduced by a decree of the rational Convention, on November the 24th, 1793. The time from which the new reckoning was to commence was the autumnal equinox of 1792, which fell upon the 22nd of September, when the first decree of the new republic had been promulgated. The year was made to consist of twelve months of three decades each, and, to complete the full number, five fete days, or sansculotides (in leap years six) were added to the end of the year. The seasons and months were as follows: Autumn; 22nd September to 22nd December Vendimiaire, vintage month; Brumaire, foggy month; Frimaire, sleet month. Winter; 22nd December to 22nd March: Nivose, snowy month; Plumose, rainy month; Ventose, windy month. Spring; 22nd March to 22nd June: Germinal, bud month; Floreal, flower month; Prairial, meadow month. Summer; 22nd June to 22nd Sept.: Messidor, harvest month; Thermidor, hot month; Fructidor, fruit month. The common Christian or Gregorian calendar was re-established in France on the 1st of January, 1806, by Napoleon.
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